Material subdividing installation



March 2, 1943. o. w. RANDOLPH MATERIAL SUBDIVIDING INSTALLATION Filed Feb. 3, 1941 2 Sheets-Sheet l March 2, 1943. o. w. RANDOLPH MATERIAL SUBDIVIDING INSTALLATION 2. Sheets-Sheet 2 Filed Feb. 5, 1941 i/M J [1/ Tami/i 3mm Patented Mar. 2, 1943 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to classifying, mixing, and handling of bulk material as from grinding or milling operations.

This invention has utility when incorporated in flow control for'efficient definite feeding, mixing, and commingling of fines.

Referring to the drawings:

Fig. l is a diagrammatic showing of a flow sheet in connection with which there is associated the mixing control herein;

Fig'. 2 is a detail view in plan, with parts broken away, of the mixer of Fig. 1;

Fig. 3 is a fragmentary end elevation from the right of Fig. 2; and

Fig. 4 is a section on the line IVIV, Fig. 2.

In the carrying out of the invention herein, say in the subdividing of material such as alfalfa, chopped feed may be received at station I ofRandolph Patent No. 2,205,175, of June 18, 1940, and elevated therefrom by pneumatic .conveyor 2 by way of duct'3 to cyclone dust collector 4 having discharge 5, at which valve control arm 6 may be operated for flow therefrom to be into duct or pants leg I or pants leg or duct 3. These ducts l, 8, have respective open spill connections 9, Ill. The open spill connection 9 is connected say through down duct II with grinder or hammer mill 12 of Randolph Patent No. 2,226,741, of December 31, 1940. Therefrom there is draw-off way l3 to pneumatic elevator l4 having riser duct 15 to cyclone dust collector ii. In practice, surplus gas and dust from the dust collector 4 may pass therefrom by riser way I1, and the solids or fragment portions, say short cuttings of alfalfa as well as the leaves, may initially preferably go to the break-down hammer mill I 2. In the instance of difliculty at the mill 12, the valve or control 6 may be operated for flow by way of the duct 8 and connection Hi to down duct l8 and by way of hopper l9 to hammer mill 20, set up in parallel with the hammer mill l2.

This stock, whether or not pre-subdivided in the hammer mill l2, say in the break-down initial operation, may now pass from the mill by take-off way 21, pneumatic; I elevator 22 and riser- 4 31 having remote from the pulley 35 gear 38 with detachable connection 39 assembling such with the shaft 36. This gear 38 is in mesh with pinion 40 having detachable connection 4| with shaft 42 in the receiver 3|. On this shaft 42 is fast the, drive pulley 35 and screw conveyor 43 in parallel with screw conveyor 31 and adjacent thereto. In practice, the clearing runs, for an 8 or 9 inch diameter conveyor, in the region of to inch for the clearance between the flights of the conveyor 31 with the conveyor 43. Wh le gear 38 and pinion 40 may be of similar d ameter for like speed of rotation in the event the conveyors 31, 43, be of similar pitch, at such time there would be equal response in withdrawing material or propelling material from the receiver 3| in opposite directions for delivery by the conveyor 31 to down duct 44 and by the conveyor 43 to down duct 45. However, in practice advantage has been experienced with retention of similar pitch for the respectiveconveyors 31, 43, and ready substitution of different diameter between the toothed means on the shafts 36, 42. In the instance hereinshown, such is taken as 2 to 1' or thereabouts, which means that the follower or driven shaft 36 operates the conveyor 31 at 1 the down spout 45.

This down spout or duct 45 herein delivers to filed March 12, 1940. However, there may be in- The valve controls 26, 21, from the discharge,

25 of the .cyclone I6 are operable not only for the down duct 28 or the down duct 30 but to control independently thereof for flow from this cyclone I6 by way of duct 52. This duct 52 has straightaway direct communication to the duct 45 and is thus an effective bypass as to the mixer receiver 3| and in feeding from this cyclone [6 directly to the shaker screen 46. The cyclone 24 from its outlet or discharge 53 has valve controls 54, 55, thereby effective to direct discharge from the cyclone 24 by way of down duct 56 to the receiver 3i, and by way of down duct 51 to discharge 58 as to a bagger, humidifier or storage; by way of down duct 59 directly to the down duct 44 in bypassing the mixer receiver 3|. Cut-off valve 60 is supplemental control against disturbance at the mixer from functioning of the cyclone 24. Likewise, slide cut-off valve 'BI is a safeguard when the down duct 52 is not in use, for eliminatlng any disturbance in the mixer 3| as from the dust collector I6.

The down spout 44 or duct from the receiver 3| may be to shaker screen 62 for thereby handling the fines of the regrind and working through for the finer grades in the meal. In the controls herein the sieves, working on such material as alfalfa, have a tendency to develop therefrom even from the screen 46 as well as from the screen 62 over way fiuff or woolly fiber portions. This may be from the screen 62 taken off only in a minor or negligible extent by down duct 63 in communication say with humidifier, storage, or packaging. More fluff passes at spout 54. Its flow in this installation is such as may be delivered to the dust collector 24 to have such pass by way of the mixer 3| in a uniformly definitely mixed relation for working into the feed. This means that there can be, uniformly disseminated throughout the entire mass, such protein or fiber material to leave the meal as low as 17 per cent or even 13 per cent. From this screen 62 as the fines are reground for supplemental effectiveness, the coarse flows therefrom by way of down the spout 64 to the hopper I! for the regrinding hammer mill 20, for ascent to the cyclone 24 and from thence to go say directly to bagger, humidifier by way of the duct 51 or again to the mixer, or directly to the screen 52 and the discharge therefrom by the way 63.

It is to be noted that as to these screens control valve 65 may cut off the spout 41, control valve 66 may cut off the spout 49, control valve 61 may cut off the spout 64, and control va ve 68 may cut off the spout 63.

The flexibility of this flow installation as adapted under the receiver and screw mixer therewith has meant in practice for subdivision of stock a saving of as much as per cent in horse power requirement for mill operation to the degree of fines, say in the handling of alfalfa lseparation initially cut to 2 inch lengths as cut green and dehydrated. With thls installation, the controls for fiow are from maximum of output with resultin efficiency therefrom, and in such controls the take-offs may be for a range or ranges of fines or'proportions of fiber as may conform to various specifications. This flexibility in control is a matter of appeal to the mill operator and of advantage in conforming to trade demands and character of stock handled.

The pneumatic elevators 2, 22, 14, in th general flow handling herein are centrifugal blowers, thereby supplying not only delivery of the stock but also sufficient air for effecting the cyclone Disturbance from this blower 2 into the cyclone 4 is not transmitted to the hammer mill l2 or 20 due to the open connections 9, it]. In the practice hereunder, the control may be selective for all to go to the mill l2 from the cyclone dust collector 4, or such fiow diverted from flow into the duct 1 for emergency flow into the duct 8 as shown by the position of the control handle 6 (Fig. 1). As the equipment for grinding operation proceeds in its functioning for continuity of handling materials, there may be equalization of the loads in the various elements of grinders and screens as well a to the character of stock to be worked out from the mill. To such end, the mill 2!] may be the regrind wholly or nearly so, while the mill I2 is for the initial break-down. In working up this character for output, homogeneity throughout is important, and the mixer receiver 3| is efiicient to such end. There may be original break-downs from the mill i2 supplied by the duct 30 to be commingled with regrinding portions from the duct 56. Such may be delivered in proportions or selectively as desired to the respective or selected screen.

The range of simplifying herein extends not only to installation but to the operation. For the installation the drive from the motor 32 may be at such speed reduction as to rotate the shaft 42 at say 300 R. P. M. Whether the shaft 36 be rotated or disconnected, this operation of the shaft 42, due to the screw conveyor 43, is effective for conducting spill from the spout 56 over into spill from the spout 30 and so commingling such that there is uniform dissemination of the portions commingled in the discharge 45. In the event the shaft 36 be simultaneously operating with the shaft 42, the screw conveyor 31 likewise, although as specifically shown it is at a reduced rotative rate, draws its one-half proportion of the mixer quantity not only, from the down spout 36 but from the down spout 56 so that there is discharge into the down spout 44 of one-third uniformly mixed for the sifter 62 as against the two-thirds proportion in the spout 45 for the greater capacity or two deck sifter 46. A factor in contributing to this mixing, especially when the conveyor 43 is working simultaneously with the conveyor 31 is the urge from the direction of rotation of these screw conveyors upward and outward, which promotes the mixing as a loosening action as the material receiving sides of the conveyors travel upward and away from each other. This works out as effective for reducing the actual running of the fines and seems so to divide up the coarser that in the handling, even to the milling operations, such is a minimum. This in practice has resulted in higher carotin content for the feed, which can accordingly be run for a higher proportion, say of 20 per cent protein value, from alfalfa as cut green and dehydrated.

For simplifying the installation as against clogging anywhere or back due to improper shifting of slides, there is proper experience to elimihate the slide valves 60, 6 l as to the supply to the mixer and the slide valves 65, 66, 61, 68, in the discharges from the screens or sifters. However, in the working of the stock to eliminate the portions not going through the screens or to select such as coarse, the down spout 49 may be shifted from its spill connection 68 as to the mill 20 and thus have spill therefrom go to the bagger, storage, or other disposal. Likewise as to the down spout 64, wherein this fluff or carry-over is even more pronounced than from the sifter 46. Accordingly, in the shifting of this spout 64 away from delivery to the mill l9 as permitted by the connection 69, this flow from the spout 64 may be bagged, put in storage, or have other removal from further flow in the installation hereunder.

What is claimed and it is desired to secure by Letters Patent is:

1. A comminuting system for pre-cut bulk vegetable material consisting of a dust collector provided with a material inlet and a plurality of material outlets, a fan means with an elevating conduit, said conduit delivering material upwardly to the inlet of the dust collector, two outlet conduits leading downwardly from the material outlets of the dust collector, valve means to deliver material from the collector into either of the two conduits; a primary impact mill and a secondary impact mill, conduit feed means for each mill, interconnections between one of each conduit feed means and one of each outlet conduits from the dust collector; discharge means leading from each mill comprising a fan and an elevating conduit; a pair of dust collectors each provided with a material inlet and a plurality of material discharge outlets, inter-connections between one of the elevating conduits of each mill and the material inlet of one of the paired dust collectors, a plurality of discharge conduits from each of the paired collectors, proportioning means in communication with one discharge conduit from each of the paired collectors, a pair of screen units, interconnecting conduits between the proportioning means and each of the paired screens, interconnections between another delivery conduit from each of the paired collectors to each of the paired screens, each of said latter inter-connections being provided with a shut off means, a finished material conduit leading from beneath each screen to discharge the troughs from each screen,

a recirculating conduit leading from above each screen to the conduit feed means on the secondary mill.

2. In combination a pair of mills, a pair of dust collectors, a conduit with pneumatic means to convey pulverized material from each mill to each dust collector, a housing enclosing a mixing and proportioning device, a conduit connecting each collector with said housing to convey solids to the proportioning device, a pair of separate screens, a conduit connecting the proportioning device with each screen, means in the proportioning device to mix materials and proportion the same to each of the last mentioned conduits; a second conduit leading from each collector to the housing of the proportioning device and positioned to discharge directly into one of the conduits connecting the proportioning device with a screen, valve shut off means in each of said second conduits positioned at entrance of said proportioning device, a conduit arranged to receive the overs from each screen and convey same to one of the mills and another conduit arranged to receive throughs from each screen and discharge same as finished product.

OLIVER W. RANDOLPH. 

